1. Field of the Invention
The present invention concerns low temperature stable organic polyisocyanates. More particularly, the present invention relates to low temperature stable polymethylene polyphenylene polyisocyanates and to polyurethane foams prepared therefrom.
2. Prior Art
U.S. Pat. No. 3,449,256 teaches a process for the preparation of polyisocyanates stable at a temperature of about 15.degree. C. The present invention relates to compositions of polyisocyanates which are stable at temperature of 0.degree. C. for at least two weeks.
U.S. Pat. No. 4,448,938 teaches of an isocyanate composition having low temperature stability wherein the composition is composed of a mixture of a reaction product of diphenylmethane diisocyanate with a polyether of an alcohol or amine of molecular weight 600 to 10,000 and a uretonimine modified diphenylmethane diisocyanate.